Various imaging systems and tools have been developed to assist physicians, clinicians, radiologists, etc. in evaluating medical images to diagnose medical conditions. For example, computer-aided detection (CAD) tools have been developed for various clinical applications to provide automated detection of abnormalities in medical images, such as colonic polyps and other abnormal anatomical structures such as lung nodules, lesions, aneurysms, calcification, in breast, heart or artery tissue, etc.
A common medical imaging technique is magnetic resonance imaging (MRI), which uses a powerful magnetic field to image the internal structure and certain functionality of a body. MRI is particularly suited for imaging soft tissue structures and is thus highly useful in the field of oncology for the detection of breast lesions.
Dynamic contrast-enhanced MRI (DCE-MRI) allows for many additional details pertaining to bodily soft tissue to be observed, to further aid in diagnosis and treatment of detected lesions. DCE-MRI may be performed by acquiring a sequence of magnetic resonance (MR) images that span a time before a magnetic contrast agent is introduced into the patient's body and a time after the magnetic contrast agent is introduced. By imaging the patient's body sequentially, a set of images may be acquired that illustrate how the magnetic contrast agent is absorbed and washed out from various portions of the patient's body. This absorption and wash-out information may be used to characterize various internal structures within the body and provide additional diagnostic information.
When radiologists read DCE-MR images, the first decision to make is typically to determine whether a lesion is a mass or a non-mass-like enhancement (NMLE). According to the Breast Imaging Reporting and Data Systems (BI-RADS) lexicon developed by the American College of Radiology (ACR), a mass refers to a three-dimensional space-occupying lesion formed by a single process, while an NMLE refers to an enhancement of an area that is not a mass, formed by multiple processes. For example, in a cancerous NMLE lesion, multiple cores where the cancer started its growth can be observed.
Regardless of whether radiologists base their descriptions on the BI-RADS lexicon, the discrimination between a mass and an NMLE is important because a mass is connotative of more malignancy than an NMLE. For example, a mass may be an invasive carcinoma, while an NMLE may be a carcinoma in situ, which is less malignant than an invasive carcinoma. When a benign lesion is a mass, it is often a fibroadenoma; a benign NMLE object may be a mere post operational scar.
Therefore, based on the discussion above, there is a need for a technology that automatically discriminates between a mass and an NMLE.